Resumo

Meat consumption has been declining in favor of a shift towards poultry due to its lower price, health benefits and consumers' preference. One of the ways to enhance broiler production and quality is to substitute standard maize (SM) with quality protein maize (QPM) in animal diets. QPM is a high lysine maize with improved nutritional and biological values, developed by the selection of a naturally occurring recessive opaque2 mutation, which can reduce the use of costly feed components - synthetic lysine and protein ingredients such as soybean and fishmeal. Different feeding trials with QPM in broiler diets indicated that body weight gain (BWG), feed conversion ratio (FCR), breast meat yield (BMY), and abdominal fat (AF) are the main improved features. Herein, an overview of the effects of QPM on broiler performance and carcass characteristics, as well as the financial effects of its use, is presented. Different effects of QPM were observed, depending, in the main, on the QPM hybrid used in the trial. The possible reasons for the discrepancies and suggestions for overcoming them, focused on the utilization of the full potential of QPM, are discussed.

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A total of 860 Embrapa 051 pullets were allocated into three groups based on their 19-week body weights (heavy: 1.48 kg ± 0.01 SD, N= 172 birds, medium: 1.32 kg ± 0.039 SD, N= 516 birds, light: 1.19 kg ± 0.019 SD, N=172 birds) and housed in floor pens with nests for a 65-week production period. Heavy-weight birds exhibited higher egg production during weeks 24-28, while medium-weight hens surpassed heavy-weight counterparts between weeks 41-46, and light-weight hens outperformed heavy-weight birds in weeks 61-65. From weeks 57-65, no significant egg production differences were noted between heavy and medium-weight hens. Body weight at 19 weeks affected floor eggs, cracked eggs, and double-yolk eggs (P < 0.05) during weeks 22-34. Heavy-weight hens laid fewer floor eggs, medium-weight hens had fewer cracked eggs (0.3%), and light-weight hens produced fewer double-yolk eggs (1.1%). No significant impact of weight grouping on egg weight was observed. Results indicated that body weight at 19 weeks influences the laying cycle, with heavy, medium, and light-weight hens exhibiting distinct egg production patterns, nest use and egg quality traits at different phases of the cycle.

Oitocentas e sessenta frangas Embrapa 051 foram alocadas em três grupos de peso corporal às 19 semanas (pesadas: 1,48 kg ± 0,01 DP, N= 172 aves, médias: 1,32 kg ± 0,039 DP, N= 516 aves, leves: 1,19 kg ± 0,019 DP, N=172 aves) e alojadas em piso com ninhos por 65 semanas. As aves pesadas apresentaram maior produção de ovos nas semanas 24-28, enquanto as médias superaram as pesadas nas semanas 41-46, e as leves superaram as pesadas nas semanas 61-65. Nas semanas 57 a 65, não houve diferenças significativas na produção de ovos entre as aves pesadas e médias. O peso às 19 semanas afetou ovos no chão, ovos trincados e ovos duplos (P < 0,05) nas semanas 22-34. As aves pesadas botaram menos ovos no chão, as médias tiveram menos ovos trincados (0,3%), e as leves produziram menos ovos com duas gemas (1,1%). Não houve impacto significativo do peso inicial no peso dos ovos. Em conclusão, o peso às 19 semanas influencia o ciclo de postura, com aves pesadas, médias e leves exibindo padrões distintos de produção de ovos, uso do ninho e características de qualidade em diferentes fases do ciclo.

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Evaluated different feed forms (FF), (mash or pellets), feeding systems (FS) (ad libitum or controlled) and metabolizable energy levels (ME) (2,900 kcal/kg or 2,750 kcal/kg) in rearing period 1 (7 to 12 weeks) and 2 (13 to 17 weeks). Utilized 400 brown-egg laying pullets a completely randomized design in 2x2x2 factorial arrangement (eight treatments, with five replications). In period 1, feed intake was similar (P > 0,05) between FF and between ME, however pullets fed ad libitum showed 27.5% higher intake than fed with controlled amounts (P < 0,05). Body weight (BW) differed (P < 0.05) in the FS. Feed conversion (FC) was not affected (P > 0.05) by any of the study factors. Flock uniformity was affected (P < 0.05) by FF and by FS, with an interaction between the factors (P < 0.05). The pullets fed the mash feed ad libitum had better uniformity (P < 0.05) than the pullets fed with the controlled mash feed. The pelleted feed caused the worst uniformity. In rearing period 2, feed intake was affected (P < 0.05). That pullets fed mash or pelletized feed ad libitum consumed 8g more (P < 0.05) on average, than those in the controlled FS. In the ad libitum supply, intake was higher (P < 0.05) for the mash feed than for the pelleted feed. BW and FC were not affected by any of the factors (P > 0.05). Uniformity (%) was influenced by the mash or controlled systems (P < 0.05). Between 7 and 17 weeks of age, brown-egg laying pullets need to be fed with a mashed diet in a controlled feeding system, with 2,750 kcal/kg of metabolizable energy.

Foram avaliadas diferentes formas de ração (FA), (farelo ou pellets), sistemas de alimentação (SA) (ad libitum ou controlado) e níveis de energia metabolizável (EM) (2.900 kcal/kg ou 2.750 kcal/kg) nos períodos de criação 1 (7 a 12 semanas) e 2 (13 a 17 semanas). Foram utilizadas 400 frangas poedeiras semipesadas em delineamento inteiramente casualizado em arranjo fatorial 2x2x2 (oito tratamentos, com cinco repetições). No período 1, o consumo de ração foi semelhante (P > 0,05) entre FA e entre SA, porém frangas alimentadas ad libitum apresentaram consumo 27,5% maior do que as alimentadas com quantidades controladas (P < 0,05). O peso corporal (PC) diferiu (P<0,05) no SA. A conversão alimentar (CA) não foi afetada (P > 0,05) por nenhum dos fatores do estudo. A uniformidade do lote foi afetada (P < 0,05) por FF e por FS, com interação entre os fatores (P < 0,05). As frangas alimentadas com ração farelada ad libitum apresentaram melhor uniformidade (P < 0,05) do que as frangas alimentadas com ração farelada controlada. A ração peletizada causou a pior uniformidade. No período de recria 2, o consumo de ração foi afetado (P < 0,05). As frangas alimentadas com ração farelada ou peletizada ad libitum consumiram 8g a mais (P < 0,05) em média, do que aquelas no FS controlado. No fornecimento ad libitum, o consumo foi maior (P < 0,05) para a ração farelada do que para a ração peletizada. O PC e o FC não foram afetados por nenhum dos fatores (P > 0,05). A uniformidade (%) foi influenciada pelo sistema farelado ou controlado (P < 0,05). Entre 7 e 17 semanas de idade, as frangas poedeiras de ovos vermelhos precisam ser alimentadas com dieta farelada em sistema de alimentação controlado, com 2.750 kcal/kg de energia metabolizável.

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The present study evaluated the effectiveness of using disposable masks in mitigating the spread of Staphylococcus aureus during the chicken cutting process in a large poultry abattoir. The identification of carriers of S. aureus and the influence of the time of use of disposable masks was carried out. Contamination of utensils and equipment by S. aureus and products by mesophilic aerobes was determined, with and without the use of masks. The efficiency of different commercial masks was evaluated against S. aureus under simulated conditions. The results revealed that 36% of workers on processing lines at the abattoirs carried S. aureus. An increase in S. aureus counts was observed in masks worn by employees for up to 3 h. The transfer of microbial load to utensils was enhanced in the absence of the mask and over time. The breast fillets evaluated showed no difference in the count of mesophilic bacteria with and without the use of masks by employees, conversely, the cuts of thigh and drumstick, thigh fillet and drumstick and wings showed a significant difference with average counts lower than 2 .96 Log CFU/g. Tests under simulated conditions demonstrated the effectiveness of commercial masks in retaining microorganisms. The test mask used by the abattoirs proved to be inefficient, allowing the passage of sprays containing S. aureus, at 6, 15 and 25 cm, with 2.53, 1.74 and 0.66 Log CFU/plate, respectively. This mask saturated, creating a barrier effect that increased contamination in the employees' work area.

O presente estudo avaliou a eficácia do uso de máscaras descartáveis na mitigação da propagação de Staphylococcus aureus durante o processo de corte de frango em um grande abatedouro de aves. Foi realizada a identificação de portadores de S. aureus e influência do tempo de uso de máscaras descartáveis. A contaminação em utensílios e equipamentos por S. aureus e produtos por aeróbios mesófilos foi determinada, com e sem uso de máscaras. A eficiência de diferentes máscaras comerciais foi avaliada contra S. aureus em condições simuladas. Os resultados revelaram que 36% dos trabalhadores das linhas de processamento no frigorífico eram portadores de S. aureus. Foi observado aumento na contagem de S. aureus em máscaras usadas pelos funcionários até 3 horas. A transferência de carga microbiana para utensílios foi potencializada na ausência da máscara e com o passar do tempo. Os filés de peito avaliados não apresentaram diferença na contagem de bactérias mesófilas com e sem o uso de máscaras pelos funcionários, por outro lado, os cortes de coxa e sobrecoxa, filé de coxa e sobrecoxa e asas apresentaram diferença significativa com contagens médias inferiores a 2,96 Log de UFC/g. Testes de condições simuladas demonstraram a eficácia das máscaras comerciais na retenção de microrganismos. A máscara teste utilizada pelo frigorífico mostrou-se ineficiente, permitindo a passagem de pulverizações contendo S. aureus, a 6, 15 e 25 cm, com 2,53, 1,74 e 0,66 Log UFC/placa, respectivamente. Essa máscara saturava, criando um efeito barreira que aumentava a contaminação na área de trabalho dos funcionários.

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This study compares the physicochemical characteristics of breast meat (Pectoralis major) from conventional chicken and free-range chicken production systems. Analyses of pH, instrumental color measurement, weight loss from cooking (WLC), and water retention capacity (WRC) were carried out. Average pH values were slightly higher for conventional chicken samples. WLC did not show a significant difference between conventional and free-range chicken samples. The WRC was better and higher for the free-range chicken samples than the conventional ones. The mean values for luminosity (L*) were within the normal range, with slightly higher values for conventional chicken. In chromatids a* and b*, there was a tendency towards a more reddish color for free-range chicken samples. The differences found for types of production can be explained mainly by the difference in age at slaughter, the degree of physical activity, animal feeding, among other characteristics that differentiate an animal raised by the extensive system from the intensive system.

Este estudo compara as características físico-químicas da carne de peito (Pectoralis major) de frangos de granja e caipiras. Foram realizadas análises de pH, medição de cor instrumental, perda de peso por cocção (PPC) e capacidade de retenção de água (CRA). Os valores médios de pH foram ligeiramente maiores para as amostras de frango de granja. PPC não apresentou diferença significativa entre as amostras de frango de granja e frango caipira. O CRA foi melhor e maior para as amostras de frango caipira do que para as amostras de frango. Os valores médios de luminosidade (L*) ficaram dentro da normalidade, com valores ligeiramente superiores para frango de granja. Nas cromátides a* e b*, houve uma tendência de coloração mais avermelhada para as amostras de frango caipira. As diferenças encontradas para os tipos de produção podem ser explicadas principalmente pela diferença de idade ao abate, grau de atividade física, alimentação do animal, entre outras características que diferenciam um animal criado pelo sistema extensivo em relação ao sistema intensivo.

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This study aimed to assess the impact of various conservation methods on water uptake, nutritional, and microbiological content in intact or cut carcasses from broiler managed to Amazon environmental conditions. The experiment involved 48 carcasses, employing a randomized block design with a factorial scheme (2x3) based on carcass processing (intact or cut) and conservation methods (freezing, on ice, or chilling). Chilled storage led to significantly higher (p<0.05) water uptake, particularly in the short term, without adversely affecting nutritional content. Freezing yielded lower (p<0.05) water uptake, with greater (p<0.05) nutritional content, while on-ice storage exhibited satisfactory nutritional content but higher microbiological contamination. Cut carcasses displayed higher (p<0.05) short-term water uptake without detrimental effects (p<0.05) on nutrition and microbiology. Conversely, intact carcasses exhibited lower (p<0.05) water uptake in the short and long term, slightly diminished (p<0.05) nutritional content, and increased (p<0.05) microbiological contamination.

Este estudo teve como objetivo avaliar o impacto de vários métodos de conservação na absorção de água, no conteúdo nutricional e microbiológico em carcaças inteiras ou cortadas de frangos de corte manejados nas condições ambientais da Amazônia. O experimento avaliou 48 carcaças em delineamento em blocos ao acaso, com esquema fatorial (2x3), com os tratamentos baseados no processamento da carcaça (inteira ou cortada) e nos métodos de conservação (congelamento, gelo ou resfriamento). Nos resultados, o armazenamento refrigerado levou a uma absorção de água significativamente maior (P<0,05), particularmente em curto prazo, sem afetar negativamente o conteúdo nutricional. O congelamento proporcionou menor (P<0,05) absorção de água, com maior (P<0,05) conteúdo nutricional, enquanto o armazenamento em gelo apresentou conteúdo nutricional satisfatório, mas maior contaminação microbiológica. As carcaças cortadas apresentaram maior (P<0,05) absorção de água em curto prazo, sem efeitos prejudiciais (P<0,05) no seu conteúdo nutricional e na concentração microbiológica. Por outro lado, as carcaças inteiras exibiram menor (P<0,05) absorção de água em curto e longo prazo, conteúdo nutricional ligeiramente diminuído (P<0,05) e aumento (P<0,05) na contaminação microbiológica.

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This study aimed to analyze the economic viability of the implementation of a mechanized harvesting of broilers where the activity is carried out entirely manually. The viability indicators used were net present value (NPV), net future value (NFV), net uniform value (NUV), discounted payback (DP), and internal rate of return (IRR). Scenario analysis, sensitivity, and Monte Carlo simulation were performed in the present study. The results showed that the initial investment was US$ 1,868,302.76. The average price paid by the slaughterhouse to third-party manual harvesting companies was US$ 18.17 per thousand broilers, which was converted into revenue in the cash flow of the project. The cash flow result was positive at US$ 22,256.14 over the entire study period considering a daily catch of 144 thousand broilers. The results of the economic viability analysis were NPV of US$ 64,786.23, NFV of US$ 333,382.11, NUV of US$ 735.19, DP of 13.82 years, IRR of 0.965 monthly, and modified IRR of 0.933 monthly. These values prove the economic viability of implementing the project considering the market conditions at the time of the study. The analysis of scenarios showed great sensitivity to the exchange rate and the price of fuels. The Monte Carlo simulation highlighted a moderate risk of negative NPV, emphasizing the importance of considering this variable when making decisions. Despite these challenges, the potential benefits of mechanized harvesting, such as increased efficiency and reduced labor costs, make it a promising alternative to manual harvesting, even for small to medium-sized poultry industries.(AU)

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Livestock and poultry production are critical agricultural industries. Intelligence in the poultry industry has received increasing attention in recent years. An intelligent monitoring system was implemented to manage the poultry house and improve its feeding conditions. Experts can remotely diagnose the health of chickens using a monitor screen. An intelligent video surveillance system was used in this study to evaluate the physical appearance of broilers in a poultry house. Comb color was studied during the long chicken growth phase, and color changes were statistically analyzed. The video surveillance system includes meticulously color-calibrated cameras with an additional YOLOv4 algorithm for comb detection and color recovery. The image data was stored for up to 90 days and then analyzed to understand comb color behavior during growth. This study develops a technique for automatically extracting comb colors that can assist professionals in making color-related broiler health diagnoses in the future.(AU)

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Sidewall openings play an important role in the indoor conditions of livestock buildings. It influences airflow patterns, air velocity distribution at the animal-occupied zones and the illumination level in the naturally ventilated animal building. However, there is a paucity of information on the effects of sidewall opening areas on the performance of broiler chickens. Hence, this study investigated the effect of sidewall opening areas on the indoor condition and the body growth of broilers. Two buildings with different sidewall opening areas were developed with broiler chickens reared in them for 28 days. The results showed that air temperatures and relative humidity of the buildings were influenced by the outdoor temperature. The indoor air temperatures of the building exceeded the recommended thermal conditions (18 to 24ºC) for broiler chickens. Similarly, the temperature-humidity index of the building exceeded 21.0ºC recommended for broilers which could result in heat stress and poor performance of broiler chickens during extremely hot weather periods. It was also found in this study that broiler chickens could not perform optimally though they were fed ad libitum. Therefore, further studies are required to ascertain the impact of sidewall opening areas on broiler performance, behaviour and physiological responses.(AU)

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The aim of this study was to determine the meat quality characteristics of broilers that were brought to the slaughterhouse from different transport distances and received post-slaughter carcass electrical stimulation. For this purpose, broilers were transported to the slaughterhouse from different distances, from farms belonging to the same enterprise. Broilers coming from different distances were randomly divided into two subgroups after slaughter. Electrical stimulation was applied to one of the groups, on the pectoral muscle. After electrical stimulation, pH measurements of the carcasses were made in both groups in the first 15 minutes. The carcasses were then cut, and the breast and thigh meats were separated. Subsequently, these samples were kept at +4°C for 24 hours, and pH measurements, electrical conductivity, color parameters, cooking loss and texture profile analyses were made. For the breast meat samples, it was determined that the difference in transport distance between the groups caused a difference in crude protein, crude fat, and crude ash values. It was detected that as the transport distance to the slaughterhouse increased, the protein and ash values decreased, while the fat value increased. pH15min was measured to be lower in breast meat samples taken from a closer distance to the farm. In thigh meat samples, the difference in transport distance was significant in crude fat and crude ash values. It was determined that the difference between the groups in the values obtained as a result of the electrical stimulation applied after slaughter were not significant, except for redness values of thigh meat.(AU)

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Salmonella spp. is one of the major bacterial causes of foodborne gastroenteritis in humans. The aim of this study was to investigate antimicrobial susceptibility to cephalosporins and quinolones, and to identify the genetic mechanisms related to this resistance in strains of Salmonella spp. Seventy chicken carcass samples were collected from slaughterhouses in the state of Rio de Janeiro, Brazil. The phenotypic profile was detected by the disk-diffusion method and the search for genes encoding betalactamases, and resistance to quinolones was evaluated by PCR. The search for mutations in gyrA and parC was carried out by sequencing these genes. Eleven strains of Salmonella spp. of different serotypes were isolated. All the strains were resistant to at least one of the antimicrobials tested, and 63.64% (7/11) showed resistance to three or more antimicrobials. In the phenotypic test for ESBL production, 36.36% (4/11) of the strains were considered positive. PCR detected the resistance genes bla CMY-2, qnrB, bla CTX-M, and bla TEM. Among the isolates, 45.45% (5/11) simultaneously presented the bla CTX-M, bla TEM, qnrB genes and a mutation (Thr-57→Ser) in parC. Point mutations in the parC gene were detected in all the analyzed samples. Genes such as bla SHV, qnrA, qnrC, qnrD, qnrS, aac(6')-Ib, qepA, and oqxAB were not detected. The study identified Salmonella spp. resistant to cephalosporins and quinolones, with resistance genes and mutations in parC, highlighting concerns about the adoption of biosecurity measures, responsible use of antimicrobials, and surveillance of resistant strains in the poultry chain.(AU)

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The current investigation aimed to explore the effects of Myrciaria dubia liquid extract (MDLE) as the primary component of an extender for breeder rooster semen over different periods at room temperature. Fifteen breeder roosters (40 weeks of age, average body weight of 2.05±0.12) with confirmed fertility were used. Employing a factorial design (3x4), the treatments consisted of semen in natura and two semen extenders (an experimental based on MDLE and a commercial) subjected to four periods at room temperature post-collection (5, 10, 15 and 20 minutes) with four replicates (tubes) each. All variables evaluated in this study yielding significant results (p<0.05). Analyzed individually, the experimental extender based on MDLE exhibited a linear reduction (p<0.05) in motility and vigor results, while it caused an increase in pH values and percentages of sperm defects evaluated. When compared with semen in natura and commercial extender, the efficiency of MDLE as a semen extender was inferior to that observed with the commercial extender and similar to the results observed with semen in natura. Nonetheless, the experimental extender based on MDLE yielded satisfactory results for up to 15 minutes of storage time. In conclusion, MDLE can be considered as an alternative for composing a roosters' semen extender, maintaining sperm characteristics within acceptable limits for up to 15 minutes at room temperature. However, this experimental extender demonstrated lower efficiency than the commercial extender in maintaining the sperm quality at room temperature across all periods tested.(AU)

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This study evaluated heterosis and reciprocal effects in across of White Leghorn with Fayoumi, White Leghorn with Koekoek in comparison to their pure line breeds for the productive and reproductive traits. Data were purposively collected from 357 layers based on their genetic groups and each genotype was reared in three replicates on a deep litter system from 20-72 weeks. Results showed that genotype groups were found to have no significant differences (p > 0.05) for age at first egg (AFE) and hen- housed egg production (HHEP). Purebred Koekoek and crossbred of male White Leghorn and female Koekoek were superior for body weight at first egg (BWAFE). Purebred Fayoumi has exhibited the least values for egg number. Purebred White Leghorn was the best by their feed conversion ratio. Effects of heterosis were non-significant (p > 0.05) for AFE and BWAFE, and hen-housed egg production. A negative heterosis percentage was noted for AFE in all crossbred genotypes. Crossing between male Koekoek and female White Leghorn gave the highest heterosis effect for feed intake while crossing between male White Leghorn and female Fayoumi gave the highest estimates of heterosis for total egg number per hen. The main crossbred between male White Leghorn and female Fayoumi hybrids outperformed in AFE and HHEP while the main crossbred between male White Leghorn and female Koekoek outperformed in BWAFE and HHEP. On the contrary, reciprocal crossbreds between male Fayoumi and female White Leghorn and male Koekoek and female White Leghorn had higher feed intake and better feed conversion ratio.(AU)

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This study was aimed at assessing the egg quality traits of Nigerian indigenous chickens raised under scavenging and improved feeding conditions in relation to exotic chicken's eggs. The study was conducted in Sam Tee farm Nukai Jalingo, Nigeria. The indigenous breed pullets were sourced from villages in Ardo Kola, Lau and Zing L.G.A. The birds were grouped into three treatments Viz: indigenous breed under improved feeding and scavenging conditions and the exotic breed. The indigenous breed pullets under improved feeding condition were placed on grower's diet and gradually replaced with a commercially prepared layers' mash. A total of 336 eggs from the three groups were examined. Eggs weight, length, width, shell thickness and yolk width were measured. Shell ratio, surface area and Haugh unit were calculated. Data were analyzed using ANOVA and correlation analysis. There were significant variations in egg weight, egg length and shell thickness between the indigenous and the exotic breed. The indigenous breed reared under improved feeding condition had the longest egg, largest surface area, thicker and heavier shell. Egg weight and surface area have significant positive correlations. In conclusion, Indigenous chickens' performance on some egg quality traits can be enhanced with judicious feeding and management.(AU)

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This work reviews the effect of environmental enrichments (perches, platforms, stocking density, outdoor access, bale, and dust bathing substrates) on the performance of fast and slow-growing commercial broiler strains. The performance of both slow and fast-growing commercial broiler strains under conventional production systems are generally poor, especially regarding the welfare status. One of the strategies to improve the performance of commercial broiler strains is by adding enrichment objects to production systems. The addition of enrichments to production systems should improve animal welfare, have no negative effect on production performance, and be both economically practicable and feasible to employ. Perches and platforms are the most common enrichments used to increase the activity of broiler chickens to improve leg conditions. The use of perches and platforms could lead to the reduction in the incidence of footpad dermatitis, hockburns and breast blisters, with subsequent effects on meat quality. Moreover, the provision of outdoor access could improve the biology responses of broiler chickens to various environmental stimuli, with a profound effect on performance and meat quality traits. Furthermore, another enrichment strategies that could increase the exploratory behavior and the general welfare of broiler chickens is the use of dustbathing and bale subtrates. Moreover, adjusting the stocking density provides broiler chickens with the necessary space for movement, reduces crowding, trampling and the associated agonistic behavior. However, the effect of some of these enrichments (perches, platform, bale) objects may vary depending on height, age, sex, and strain of the chickens.(AU)

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This study examined the effects of age, housing environment, and strain (Lohmann Sandy (LS) and Lohmann LSL Classic (LW)) on egg quality traits. Deep litter (DL), free access to outdoor Mentha piperita (MP), Petroselinum crispum (PC), and Medicago sativa (MS) vegetated environments were examined. A total of 260 four-week-old birds were randomly distributed to DL and outdoor plant-associated groups, with four and three replicates, respectively, and 10 birds per replicate. Eggs were analyzed between 26 and 52 weeks of hen age, every 4 weeks. Overall, all egg quality parameters significantly differed as hen age increased (p<0.01). The housing environment significantly influenced egg weight, shell-breaking strength, shell thickness, egg surface area, and yolk color score. Eggs obtained from DL hens were heavier and had a higher egg surface area than those from MS, PC, and MP hens (p<0.01; p<0.05). However, eggs laid by MS, PC, and MP hens had higher shell-breaking strength and thickness (p<0.01; p<0.05). DL hens had a greater ratio of eggs with meat-blood inclusions in the yolk compared to MS, PC, and MP hens (p<0.05). Shape index, albumen height, albumen index, Haugh unit, and yolk index were similar among housing environments (p>0.05). Strain significantly affected shape index, shell thickness, albumen height, albumen index, Haugh unit, albumen pH, yolk index, and yolk color score. LS eggs had higher shape index, shell thickness, yolk index, and yolk color score (p<0.01; p<0.05). However, LW eggs had greater albumen height, albumen index, Haugh unit, and albumen pH (p<0.01; p<0.05). LW strain had a lower ratio of eggs with meat-blood inclusions compared to LS (p<0.01). Shell-breaking strength and egg surface area did not differ between hen strains (p>0.05). This study showed that allowing hens access to MS, PC, or MP plant species improved shell quality traits. Moreover, it appears that there is a greater genetic variability in albumen and yolk quality traits.(AU)

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Calcium is essential for bone development and eggshell formation in laying hen nutrition. It is therefore important to align the nutritional levels of calcium and the granulometry of limestone. The aim herein was to evaluate the effect of different calcium levels and two limestone granulometries on the performance, egg quality, digestive organ characteristics, and bone quality of layers in their second production cycle. A total of 324 Lohmann LSL Lite layers at 113 weeks of age were distributed in a completely randomized design with a 3 x 2 factorial scheme, with 3 calcium levels and 2 limestone granulometries, totalling 6 treatments with 6 replicates of 9 birds each. Performance, egg quality, digestive organ biometry, and bone characteristics were evaluated. The data were submitted to analysis of variance, and the means were compared by Tukey's test. In addition, a canonical discriminant analysis (CDA) was carried out. There was no interaction between the factors for any of the variables. However, there was an effect of granulometry on egg weight, and of calcium levels on relative liver weight. No differences were observed in the CDA. It is concluded that coarse-grained limestone improves egg weight, and a 4.3% calcium level is recommended.(AU)

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Studies on consumer preferences show that eggs obtained in open areas such as free-range systems and organic systems have superior taste than cage chicken eggs. Moreover, it is emphasized that the odor characteristics of eggs obtained in different production systems are different, and this reveals the necessity of determining the relevant volatile compounds. This study aimed to characterize and compare the volatile compounds responsible for the taste and aroma of eggs obtained from cage, organic and free-range systems. 60 randomly selected eggs (20 from each group sample) were analyzed by the SPME-GC-MS device. Eight volatile compounds were detected in the free-range chicken eggs, 15 in the caged chicken eggs, and 11 in the organic chicken eggs. D-limonene and 2-Butanamine, 3,3-dimethyl- compounds were determined as the main volatile odor components in all three groups of chicken eggs. Alkanes, esters, amines, acids, alcohols, ketones, aldehydes and alkenes were determined among the volatile compound groups. Acid and aldehyde groups of volatile compounds were not detected in the free-range and organic chicken eggs, as well as the ester group in free-range chicken eggs. In this study, both volatile compound numbers and compound groups of eggs belonging to different production systems were found to be different. This causes the eggs to differ in taste and aroma.(AU)

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This experiment was conducted to evaluate the welfare and production performance of broilers reared under different stocking densities. A total of 1242 one-day-old Cobb500 broiler males were distributed randomly among four treatments with nine replicates each. The treatments consisted of different broiler stocking densities (10.41; 11.45; 12.50 and 13.54 birds/m²). The parameters evaluated were regadring production performance (body weight, body weight gain, feed intake, feed conversion ratio, uniformity, and carcass yield), animal welfare (cortisol, lactate, total protein, albumin, glucose, triglycerides, cholesterol, uric acid seric, and hemogram), and litter quality (temperature, humidity, and volatilized ammonia concentration). The broilers reared at 12.5 birds/m2 presented the best feed conversion ratio at 42 days of age. Neither the carcass traits nor the stress parameters studied were influenced by the stocking densities. It was concluded that the stocking density of 12.50 birds/m² results in the best feed conversion ratio among the studied treatments for the production cycle of 42 days.(AU)

Resumo

This study was conducted to determine the effects of housing systems (free-range and conventional cage) during the egg-laying phase on the growth, egg production, overall egg weight, and egg quality traits of a new Turkish laying hen hybrid, Akbay. A total of 600 (300 hens per housing system) Akbay laying hen hybrids were used in this study. At the end of the rearing cycle (17 weeks) the average live weight and cumulative feed intake for both groups were 1150.8g and 5067.52g, respectively. The live weight and cumulative feed intake at the onset of laying for both groups were 1198.42g and 5537.77g, respectively. Egg production, average daily feed intake, and average daily feed conversion ratio were significantly higher (p≤0.05) in free-range hens than in hens housed in cages. The live weight at peak production was significantly higher (p≤0.05) in hens housed in cages than in free-range hens. Significant differences (p≤0.05) in terms of internal and external egg quality traits were observed between the housing systems in this study. Generally, the free-range hens had better performance than the hens in cages. It was therefore concluded that the growth performance, egg production, overall egg weight, and egg quality traits of the new Turkish laying hen hybrid Akbay are better in the free-range production system than in convention cages; and that these hens can be housed in the free-range system without any negative effect on performance and egg quality traits.(AU)